Examples of known molding systems are (amongst others): (i) the HyPET™ Molding System, (ii) the Quadloc™ Molding System, (iii) the Hylectric™ Molding System, and (iv) the HyMet™ Molding System (which is a metal-molding system), all manufactured by Husky Injection Molding Systems (www.husky.ca).
U.S. patent application Ser. No. 2002/0189781 (Inventor: Shibata et al; Published: Jun. 19, 2002) discloses a method for manufacturing a mold of a metal hot-runner injection molding machine. The method includes: (i) measuring a temperature gradient of metal disposed in a nozzle between heating means of the nozzle and a tip of the nozzle, (ii) selecting an area in the nozzle based on the measurement of the temperature gradient such that the metal in the nozzle upon a mold opening has a temperature at which a solidified condition of the metal can be stably maintained, said temperature being close to a melting temperature of the metal, and (iii) determining a gate cut portion in the area.
U.S. Pat. No. 6,529,796 (Inventor: Kroeger et al; Published: Mar. 4, 2003) discloses an injection mold apparatus that has multiple injection zones, each zone having at least one heater and at least one temperature sensor generating a temperature indicating signal. A power source provides power to the heaters. A controller controls the temperature of at least some of the zones. For efficiency, the controller has two separate processors, a data-receiving processor for receiving temperature indicating signal from each sensor as well as power signals, and a control processor for receiving data from the data-receiving processor and for controlling the amount of power provided to the heaters. Preferably, the control is in a housing, with the housing mounted directly on the mold. Modified PID calculations are utilized. Power calculations for the amount of power to the heaters utilizes a modulo based algorithm.
U.S. patent application Ser. No. 2003/0206991 (Inventor: Godwin et al; Published: Nov. 6, 2003) discloses an improved mold manifold and hot runner nozzle using thin film elements include at least one active or passive thin film element disposed along a melt channel between the manifold inlet and the hot runner nozzle. Preferably, the thin film element may comprise a thin film heater in direct contact with the molten resin and position to aid in the heat and flow management of the resin within the melt channel. Thin film temperature sensors, pressure sensors, and leak detectors may also be provided in the vicinity of the melt channel to enhance process control in the injection molding machine.
U.S. Pat. No. 6,533,021 (Inventor: Shibata et al; Published: Mar. 18, 2003) discloses a mold for a metal hot-runner injection molding machine. The mold includes a movable mold plate, a fixed mold plate having a nozzle for injection molten metal into said cavity, and a heating device disposed outside the nozzle for heating metal. A gate cut portion is situated in the nozzle between the heating device and the tip. A temperature measurement device is arranged adjacent to the gate cut portion for measuring the temperature of the metal in the gate cut portion. A heating control device is connected to the heating device for controlling a temperature of the nozzle on a basis of the temperature measurement device. A heat insulation device is arranged on the nozzle to cover at least an area where the gate cut portion is formed. By controlling the temperature of the nozzle, metal injection molding without runner can be made.
U.S. Pat. No. 6,649,095 (Inventor: Buja; Published: Nov. 18, 2003) discloses a method and apparatus for controlling a mold flow process using inner (impinge) and/or edge temperature sensors, wherein articles processed in a constraining mold cavity, having a constant melt “shrink” quality, can be obtained even with fluctuations in resin “melt” properties (flowability). At least one temperature-dependent output or “trigger” signal is sampled, and the level of the signal (e.g., temperature) initiates at least one step in the molding cycle. Using a sampling circuit, thermal waveforms are obtained from thermal sensor array data such that if a sequence of melt temperature set-point trigger times fluctuates outside control limits, then the process melt-flow is judged as a hotter/faster melt-flow or cooler/slower melt-flow injection process.
U.S. Pat. No. 6,666,259 (Inventor: Shibata et al; Published: Dec. 23, 2003) discloses a method for manufacturing a mold of a metal hot-runner injection molding machines. The method includes: (i) disposing at least one temperature control target point, as a reference for a temperature control by heating means for heating a nozzle, between the heating means and a tip of the nozzle, (ii) controlling said heating means such that upon a mold opening, at least a portion of metal adjacent to the heating means becomes a molten state and that a temperature of said temperature control target point is kept at a constant level which is lower than a melting point of the metal, (iii) measuring a temperature gradient between the heating means and the tip of the nozzle when the temperature of the temperature control target point is kept constant, (iv) selecting an area in the nozzle based on the measurement of the temperature gradient such that the metal in the nozzle upon a mold opening has a temperature at which a solidified condition of the metal can be stably maintained, said temperature being close to a melting temperature of the metal, and (v) determining a gate cut portion in the area.
U.S. patent application Ser. No. 2004/0032060 (Inventor: Yu; Published: Feb. 19, 2004) discloses a method of controlling a shut-off nozzle for hot runner systems of injection molding machines, the shut-off nozzle heaving a heating unit and a cooling unit around a gate tip thereof. The method includes the steps of: (i) heating a nozzle body to a predetermined high temperature by turning on a heater which is provided in the nozzle body, (ii) heating the gate tip having a nozzle gate, by turning on the heating unit provided around the gate tip, (iii) injecting a molten resin into a cavity of a mold through the nozzle gate, (iv) turning off the heating unit, after an injection of a predetermined amount of the molten resin into the cavity of the mold is completed, thus allowing the gate tip to start to cool, (v) operating the cooling unit provided around the gate tip, thus quickly cooling the gate tip, and (vi) opening the mold to remote a molded product from the cavity of the mold.
U.S. Pat. No. 6,936,199 (Inventor: Olaru; Published: Aug. 30, 2005) discloses an injection molding apparatus that includes a manifold having a manifold channel for receiving a melt stream of molten material under pressure and delivering the melt stream to a nozzle channel of a nozzle. A mold cavity receives the melt stream from the nozzle and the nozzle channel communicates with the mold cavity through a mold gate. A thermocouple is coupled to the mold core of the mold cavity in order to measure the temperature of the molten material in the mold cavity.
U.S. Pat. No. 6,938,669 (Inventor: Suzuki et al; Published: Sep. 6, 2005) discloses a mold-clamping process in which the mold is closed and (i) the injection-pressure increase (solidifying) process, (ii) the gate-melting process for heating the hot runner to melt the plug (metallic material) of the gate, (iii) the mold-lubricant coating process for spraying the lubricant onto the wall surface of the cavity, and (iv) the material-metering process are simultaneously carried out in parallel to each other. Thus, the molding cycle time can be reduced to a great extent.